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powerpc/e6500: kexec: Handle hardware threads 

The new kernel will be expecting secondary threads to be disabled,
not spinning.

Signed-off-by: Scott Wood <scottwood@freescale.com>
This commit is contained in:
Scott Wood 2015-10-06 22:48:12 -05:00
parent 939fbf0080
commit f34b3e19fd
2 changed files with 62 additions and 0 deletions
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16
arch/powerpc/kernel/head_64.S
View File

@ -182,6 +182,8 @@ exception_marker:
#ifdef CONFIG_PPC_BOOK3E
_GLOBAL(fsl_secondary_thread_init)
mfspr r4,SPRN_BUCSR
/* Enable branch prediction */
lis r3,BUCSR_INIT@h
ori r3,r3,BUCSR_INIT@l
@ -196,10 +198,24 @@ _GLOBAL(fsl_secondary_thread_init)
* number. There are two threads per core, so shift everything
* but the low bit right by two bits so that the cpu numbering is
* continuous.
*
* If the old value of BUCSR is non-zero, this thread has run
* before. Thus, we assume we are coming from kexec or a similar
* scenario, and PIR is already set to the correct value. This
* is a bit of a hack, but there are limited opportunities for
* getting information into the thread and the alternatives
* seemed like they'd be overkill. We can't tell just by looking
* at the old PIR value which state it's in, since the same value
* could be valid for one thread out of reset and for a different
* thread in Linux.
*/
mfspr r3, SPRN_PIR
cmpwi r4,0
bne 1f
rlwimi r3, r3, 30, 2, 30
mtspr SPRN_PIR, r3
1:
#endif
_GLOBAL(generic_secondary_thread_init)

46
arch/powerpc/platforms/85xx/smp.c
View File

@ -374,9 +374,55 @@ static void mpc85xx_smp_kexec_down(void *arg)
#else
void mpc85xx_smp_kexec_cpu_down(int crash_shutdown, int secondary)
{
int cpu = smp_processor_id();
int sibling = cpu_last_thread_sibling(cpu);
bool notified = false;
int disable_cpu;
int disable_threadbit = 0;
long start = mftb();
long now;
local_irq_disable();
hard_irq_disable();
mpic_teardown_this_cpu(secondary);
if (cpu == crashing_cpu && cpu_thread_in_core(cpu) != 0) {
/*
* We enter the crash kernel on whatever cpu crashed,
* even if it's a secondary thread. If that's the case,
* disable the corresponding primary thread.
*/
disable_threadbit = 1;
disable_cpu = cpu_first_thread_sibling(cpu);
} else if (sibling != crashing_cpu &&
cpu_thread_in_core(cpu) == 0 &&
cpu_thread_in_core(sibling) != 0) {
disable_threadbit = 2;
disable_cpu = sibling;
}
if (disable_threadbit) {
while (paca[disable_cpu].kexec_state < KEXEC_STATE_REAL_MODE) {
barrier();
now = mftb();
if (!notified && now - start > 1000000) {
pr_info("%s/%d: waiting for cpu %d to enter KEXEC_STATE_REAL_MODE (%d)\n",
__func__, smp_processor_id(),
disable_cpu,
paca[disable_cpu].kexec_state);
notified = true;
}
}
if (notified) {
pr_info("%s: cpu %d done waiting\n",
__func__, disable_cpu);
}
mtspr(SPRN_TENC, disable_threadbit);
while (mfspr(SPRN_TENSR) & disable_threadbit)
cpu_relax();
}
}
#endif